RE: XML/XSL free editor (eclipse plug-in, if possible)

I'm looking for a new XSLT IDE that integrates the new schema aware
functionality of 2.0; for example underlining any Xpath's I write that
aren't 'possible' (looking for the correct word there) according to the
given schema.  I would also like it to underline any match patterns that
aren't possible.  A bonus point would be given if I could see the
element children / attributes for the context node whilst in the middle
of writing the Xpath (with type information).

I don't know if any of the above is available now, on the horizon, or
even feasible, but they are top of my wishlist.